SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'eb683604e07f8bd5bdab34c52ff3d0c4795c1496d1a0d39c8b3dddc227bab9c4' 
  AND token = 'tLRgx/j4qAuBq/vPR6Q7ZjcadDsILb1uIBSnfQ1unlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}